The following F2 results occur from a typical dihybrid cross:

purple: A_B_ 9/16
white: aaB_ 3/16
white: A_bb 3/16
white: aabb 1/1

If a double heterozygote (AaBb) is crossed with a fully recessive organism (aabb), what phenotypic ratio is

expected in the offspring?


3 (white):1 (purple)

Biology & Microbiology

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With help from fertility specialists, a woman with very low  follicle-stimulating hormone and luteinizing hormone levels finally conceives a son. If her genetic condition is from a dominant allele and is passed on to her son, what is the likely result?  

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Biology & Microbiology

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Biology & Microbiology

Suppose a cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could be a cell from _____

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Biology & Microbiology